The amazing true story behind “End of the Spear” is ripe with dramatic possibilities. Reading it at the film’s Web site, I thought: This is fantastic. So why isn’t the movie better?

The movie is a respectable effort, well put together with production values that look better than its paltry budget. Its religious origin — it’s about Christian missionaries and was produced by a Christian organization — isn’t permitted to intrude on the story or turn it into a sermon.

Yet as directed by Jim Hanon and written by Hanon, Bill Ewing and Bart Gavigan — all more or less newcomers to the movie industry — “End of the Spear” feels only marginally uplifting and just passably enjoyable as a film. I know in my mind that these experiences were extraordinary for the people involved, but I never really feel it.

It is set mostly in 1953 in Ecuador, where a few young American couples have moved, with their small children, to serve as Christian missionaries to the native tribes. Of particular concern are the Waodani, a fearsome, warring indigenous group infamous for killing foreigners and each other almost without provocation.

Nate Saint (Chad Allen) — and yes, that was really his name — leads the group as they make their first friendly contact with the Waodani. As it happens, one of their people, Dayumae (Christina Souza), left the tribe years ago and now lives with Nate’s sister Rachel (Sara Kathryn Bakker) in nearby Quito. There’s a huge language barrier between Nate and the Waodani, but he wants to express to them that Dayumae is alive and well.

He also wants to help them. They’ve become so murderous that the Ecuadorian government is threatening to send troops into the jungles to quell them. The missionaries have begged for one last chance to get the Waodani to calm down by peaceful means.

(What the movie doesn’t address is that the Waodani weren’t just killing each other, but outsiders, too — outsiders like people from Shell Oil, who wanted to drill on their land.)

Nate also, let us not forget, wants to teach the Waodani Christianity. Here the movie occasionally lapses into just a bit of white man hubris, where the solution to all the poor benighted natives’ problems is to simply accept Jesus. (“We can’t shoot the Waodani,” Nate tells his son. “They’re not ready for heaven.”) Even as a Christian, I wince sometimes when I see things presented that way. But to the movie’s credit, it doesn’t fall into that trap very often — and besides, the Waodani are in fact murdering one another capriciously. I don’t think it’s culturally insensitive to say that they need to cut it out.

After the Waodani, led by a man named Mincayani (Louie Leonardo), turn on the missionaries, the Christians’ wives and children — including young Steve Saint (Chase Ellison), who narrates the film — move to the jungle to pick up where their husbands and fathers left off. Mincayani begins to feel guilt for his barbaric actions, and some of the tribe start to accept the simplified form of Christianity being taught. (“God” and “Jesus” are not named; instead, the missionaries speak in Waodani terms.)

But as I said, the film doesn’t feel like a religious tract. It focuses instead on people’s internal struggles with morality and rightness, and has an air of sincerity about it. The acting is credible, though the film’s shift in protagonists from Nate Saint to Mincayani to a grownup Steve Saint prevents us from getting too attached to any of them. It’s a positive movie with a positive message — and I suspect the documentary “Beyond the Gates of Splendor,” which tells the same story, is probably even better.

B-
(1 hr., 51 min.;
PG-13, violence in the form of people throwing spears at and into each other; some National Geographic-style partial nudity.)